Is there a pattern to tire discounts and rebates?

I'm thinking of getting new tires in the next year or so. Is there a typical pattern to when the best discounts/rebates for tires are available? Or is there a certain level of deal that tends to come around every so often?

Of course I understand that it's ultimately not the discount that matters, it's what you pay and what you get. :)

I'm in USA, looking for "okay" but not great tires for winter (next winter).